The Blue Nile, locally known as Abbay, is the major tributory of the great Nile river - the longest river in the world. The Blue Nile river starts from Ethiopia's lake Tana and merges with the smaller tributory White Nile at Khartoum Sudan to form the Nile River. The mysterious Nile was long hidden from Western geographers and explorers. It was not until the expeditions of such great travellers as Bruce, Burton, and Speke that the secret of this grand river—which had fascinated, and eluded, even the ancient Romans and Greeks - was revealed. It was then confirmed that the White Nile originates in East Africa's Lake Victoria, while the Blue Nile pours out of Ethiopia's Lake Tana. [Ethio Visit]